Manometer



Jan. 30, 1968 c. CLAFF 3,365,948

MANOMETER Filed June 13, 1966 INVENTOR. CLARENCE LLOYD CLAFF 5 KM QW+HJ M-+L ATTORNEYS:

United States Patent 3,365,948 MANOMETER Clarence Lloyd Claff, Van Bea] Road, Randolph, Mass. @2368 Filed June 13, 1966, Ser. No. 557,202 13 Claims. (Cl. 73401) This invention has to do with fluid-type manometers, and its principle object is to provide an improved manometer of this class in which means are provided for preventing slopping of the fluid in the manometer when the arms of the manometer are opened to another pressure.

Manometers have been known for many years, and the fluid-type customarily takes the form of a tube having upstanding arms with a fluid contained in the arms. When the pressures in each of the arms is equal, the levels of the fluids in the arms are the same. However, if one of the manometer has more pressure than the other, then the level changes as an indication of the pressure differential.

Such manometers are customarily made of the form of a U-shaped tubing, but in order to get more sensitivity, the arms of the manometer are sometimes spread apart so as to become more slanting. In connection with the latter particularly (although the same inconvenience is experienced in the U-shaped type) if there is a substantial degree of pressure differential, the fluid in one of the arms of the manometer will be considerably higher than that in the other arm. If, now, the pressure in the arm having the high level fluid changes suddenly (for example, if that particular arm is opened to air) the fluid will obviously move down in the tube, and because of its mass and general fluidity, its inertia will cause it to oscillate back and forth in the two tubes. The first of these oscillations in the other tube is apt to be rather large, and may result in an undesirable surging within the manometer tubing.

In the past, it has been customary to prevent this by opening both arms to air simultaneously by establishing a valve or petcock from each of the arms to air and then opening the valves simultaneously. This is extremely difficult to do, and generally does not result in prevention of the surging. This invention basically concerns a manometer in which means are provided to cause pressure changes in the two arms of the manometer to take place simultaneously and thus the aforesaid surging and inconvenience are avoided.

Among the several objects of invention, therefore, may be noted the following: the provision of a manometer in which means are provided for exposing both arms of the manometer to equal pressure changes in order to avoid surging of the manometric fluid; the provision of a manometer in which are provided means for equalizing the pressures in the two arms of the manometer simultaneously by a single control element; the provision of manometers of either of the above classes which can be readily made, and particularly can be made in a research laboratory using available glass tubing and elements and commonly practiced glass blowing techniques; the provision of a manometer which may be made as a unitary structure from synthetic plastics, using conventional machine shop practices; and the provision of a manometer of the last named class which may be made by molding methods instead of machining methods, if desired. Other objects and advantages will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the ap- 3,365,948 Patented Jan. 30, 1968 plication of which Will be indicated in the appended claims.

In the drawings, in which are illustrated three embodiments of the invention,

FIG. 1 is a plan view, partly in section, of a first embodiment of the invention;

FIG. 2 is an enlarged sectional view of a portion of the FIG. 1 embodiment, taken in the direction of sight lines 22 thereon, and given to illustrate certain details of construction more clearly;

FIG. 3 is a second embodiment of the invention; partly in section;

FIG. 4 is an illustrative view of a third embodiment of the invention; and

FIG. 5 is an illustrative view of one-half of a part of a fourth embodiment of the invention.

In the drawings, similar reference characters indicate corresponding parts throughout the several views of the drawings. Dimensions of certain of the parts as shown in the drawings may have been modified and/ or exaggerated for the purposes of clarity of illustration.

Referring first to FIG. 1, a manometer of this inven tion is shown having the two tubular arms 2 and 4 joined at the bottom as shown, these arms extending upwardly at an angle to each other and terminating in the ends 6 and 8 to which suitable connections may be made for connecting the manometer into systems in which pressure is to be measured. The tubes 2 and 4 with their ends 6 and S are preferably made of tubing or piping such as glass, as is customary.

Below the ends 6 and 8 there are connected into the arms 2 and 4 the secondary tubes or pipes 10 and 12, each of these arms making a fluid connection with their respective manometer arms, the upper ends of each of these tubes connecting into a valve mechanism indicated generally by numeral 14. The valve 14 has the usual form of a valve seat 16 and a rotary valve member 18 which makes an air tight engagement with the valve seat 16. Conventional means are provided at the top of the valve member 18, such as the knob 20 to assist in turning the valve member.

Formed into the periphery of the member 18 are the grooves 22 and 24, these grooves having a length such that when the valve member 181 is properly seated in the valve seat 16, the top of the grooves will be above the top of the valve seat.

As shown, the grooves 22 and 24 are diametrically opposite, and this spacing is to be used when the entry of the upper ends of tubes or arms 10 and 12 into the valve seat 16 are also diametrically opposite. However, if the entry of the ends of arms 10 and 12 are spaced diiferently than 180 apart (for example apart), then correspondingly the grooves 22 and 24 are to have the same spacing.

In regard to the dimensions of the groove 22 in respect to the bore diameter of the arms 10 and 12, this is not critical. However, it is to be noted that in view of the operation of the unit as will be described below, and since the exemplary valve 14 is a rotary valve, it is important that as the valve member 18 is turned, one longitudinal groove meets the opening into the valve seat of its respective end of the arms 10 and 12 at the same time that the other longitudinal groove meets the opening of its respective arm.

The operation of this embodiment is as follows: assuming that the valve member 18 has been turned so that the opening of the ends of arms 10 and 12 into valve seat 16 are closed, and assuming that the manometer is filled with a fluid, then when an unequal pressure is applied to the arms 2 and 4,. the liquid levels in the two arms will change, in usual manner. This change has been indicated in conventional manner by numerals 26 in the drawing. Now, assuming that the required measurements have been made, and it is desired to bring the levels back to their original equal position, the valve member 18 is turned until the grooves 22 and 24 meet the openings of the arms and 12 in the valve seat 16. Air will then be admitted simultaneously into the two arms 10 and 12 to the arms 2 and 4 above the fluid level. It is this simultaneous admission of air above the liquid levels that will prevent, or at least minimize, any surging of the fluid 26 in the arms 2 and 4. After the manometric fluid has been brought to the stable position, then the member 18 is rotated again until the grooves 22 and 24 no longer intersect the openings of arms 10 and 12 in the valve seat, and thus the manometer is closed for further pressure measurements.

It has been indicated above that the several arms can be made of glass, and the device as a whole can be readily constructed in a laboratory or in a manufacturing plant from conventional supplies. It is not necessary that the arms 10 and 12 enter the arms 2 and 4 at a slant, or enter the valve seat 16 at a slant, as shown. These arms can enter the arm-s 2 and 4 perpendicularly thereto, and also can enter the valve seat 16 perpendicularly, if desired. Also, in the drawings, the arms It?! and 12 are shown as being approximately the same size as the arms 2 and 4, but this is not necessary. Since air will be admitted simultaneously and equally into the arms 10 and 12 and thus above the levels of the manometric fluid in the arms 2 and 4, the arms 10 and 12 can be made much smaller than the arms 2 and 4, depending upon the speed with which it is desired to introduce air into arms 2 and 4 for equalization of pressures. Capillary tubing can be used for arms 10 and 12, if it is desired to admit air slowly, but simultaneously, into the arms 2 and 4. The place where the lower ends of arms 1t and 12 join the arms 2 and 4 is also not critical, but should be above the maximum rise (in one arm) of the manometric fluid, for obvious reasons.

Referring to FIG. 3, a second embodiment of the invention is shown, and in this instance the manometer takes the conventional form of a U-shape having the arms 32 and 34. Adjacent the tops of these arms the secondary arms 36 and 38 make a fluid entry with the arms 32 and 34 at their outer ends, and their inner ends are connected with a fluid passageway into the valve seat 16 which is like that of the FIG. 1 embodiment.

In this embodiment, however, the valve member is different from that shown in the FIG. 1 embodiment and comprises the tapered valve member 411 which is suitably fitted into the valve seat 16 to make an air tight engagement therewith. A radial bore 42 is formed in the member 40, and is positioned axially of the valve member 41 so that when the latter is rotated, the ends of bore 42 will meet the openings of the secondary arms 36 and 38 in the valve seat 16. A second bore, (preferably, axial of the member 40 but may be at any other angle) is provided in the member 40, this bore having one end opened to air, and the other end intersecting the bore 42.

The operation of this embodiment is the same as the FIG. 1 embodiment, and when the valve member 40 is turned so that the bore 42 is aligned with the openings of arms 36 and 38 in the valve seat 16, air will be admitted simultaneously (via the bores 42 and 44) to the arms 32 and 34 above the level of the liquid contained therein.

In regard to the bore 42, it has been indicated that this is radial, and it needs to be if the arms 36 and 38 enter the valve member 16 opposte each other. However, depending on the location of the opening of arms 36-38 into the valve seat, the bore 40 is directed to get the proper simultaneous meeting of the openings of arms 36-38. This is critical. Again, as pointed out in the FIG. 1 embodiment, the size of the bore 42 is not critical.

Referring now to FIG. 4 for a third embodiment of the invention, herein the manometer is not made of tubing or piping as are the embodiments of FIGS. 1 and 3. In this instance, the manometer comprises pipes 52 and 54 (using this word in its generic sense) which are formed in a block of plastic 56. Block 56 is preferably a clear transparent plastic which can be molded or cast, and is one that must be compatible with the manometric fluid which is used.

Bores 52 and 54 terminate at the upper surface of the block 56 either with the vertically rising termination pipes '58 and 60 as shown; or, if desired, the angle of the pipes 52 and 54 may be maintained to the top surface 62 without change. In order to make connection to pipes 52 and 54, tubes 64 and 66 may be press fitted into the terminations thereof, as shown, in conventional manner.

Molded or otherwise formed in the top portion of the block 56 is the valve seat 68. Joining the valve seat 68 with each of the pipes 52 and 54 are the secondary pipes 70 and 72, respectively.

The valve member 13 is the same as the valve member 19 of the FIG. 1 embodiment, and has the peripheral grooves 22 and 24, as described for the FIG. 1 embodiment, so disposed as to intersect the openings of pipes 70-72 simultaneously when the valve member is turned. In this instance, and also in respect to the first and second embodiments, the material of the valve member 18 is a material which is compatible with the valve seat. If the manometers of the FIGS. 1 and 3 embodiments are made of glass with the valve seat 16 thereof being of glass, then preferably the valve members should also be of glass. In the FIG. 4 embodiment, it the block 56 is of a molded clear plastic, then the valve member 18 may also be a molded plastic with lubrication used, as is conventional, to provide an air-tight fit in the valve seat.

In this third embodiment, the remarks given above in regard to the FIGS. 1 and 3 embodiments respecting the positioning of the grooves 22 of the bore 42, and the intersections of the upper ends of the secondary arms (112-12, 36-38, and 79-72) with the valve seats are also pertinent. However, it will be noted that for ease in manufacturing the FIG. 4 embodiment, it is preferred that the axes of the respective pipes lie in the same plane. By doing this, the several pipes can be suitably molded or bored in the plastic block, the latter being one piece. So, also, the valve seat 68 can be properly bored or milled in the top portion of the block 56. In this instance, by way of example only, the grooves 22 and 24 in the seat 18 for the FIG. 4 embodiment would be apart for pipes 70-72 which are 180 apart.

In respect to the FIG. 4 embodiment, it is not necessary that the structure as a whole be made of a single piece. FIG. 5 shows a portion of a fourth embodiment, in which the manometer :body itself comprises two similar halves one of which (74) is illustrated in FIG. 6. In each half, one half of the respective pipes 52, 54, 53, 60, 70, and 72 is molded or cast as indicated by numerals 52', 54', 58', 60', 70, and 72'. When the thus-formed two halves are accurately positioned with the faces 76 together, a suitable adhesive is used to firmly attach the two halves permanently. The adhesive, of course, must be compatible with the fluid to be used as the manometric fluid. After the two halves 74 are fastened together, then preferably the valve seat 78 is formed in the united block in such position that its periphery will intersect the ends of the half pipes 70 and 72. (One half of such an after-formed valve seat is indicated by the datted lines 78 in FIG. 7.)

The operation of this FIG. 4 embodiment is the same as described above for the FIGS. 1 and 3 embodiments, and has the attendant advantages.

In view of the above it will be seen that the several obiects of the invention are achieved and other advantageous results attained.

It is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings, shall be interpreted as illustrative and not in a limiting sense, and it is also intended that the appended claims shall cover all such equivalent variations as come within the true spirit and scope of the invention.

Having described the invention, What is claimed is:

l. A manometer comprising first and second pairs of pipes each pipe of the first pair having an upper and lower end, the lower ends of the first pair of pipes being connected to each other, and one end of each of the second pair of pipes connecting into the walls of the pipes of the first pair at points between the upper and lower ends of the latter; a rluid in the lower portions of the pipes of the first pair; and valve means associated with the other ends of the pipes of the second pair for closing the latter ends, said means being movable to open the latter ends substantially simultaneously to the same gas pressure external of the manometer.

2. The manometer of claim 1 in which the pipes of the first pair incline toward each other to form a V-shaped conduit.

3. The manometer of claim 1 in which said valve means is a rotary valve comprising a valve seat and a valve member rotatable therein, the upper ends of the pipes of the second pair opening into said valve seat, and said valve member being provided with grooves on its surface so positioned that when the valve member is in one position the grooves intersect the said upper ends simultaneously.

5. The manometer of claim 1 in which said valve means is a rotary val e comprising a valve seat and a valve member rotatable therein, the upper ends of the pipes of the second pair opening into said valve seat, and said valve member being provided with a bore in the body thereof, the bore having ends opening on the surface of the valve member and so positioned that when the valve member is in one position, the ends of the bore intersect the said upper ends simultaneously.

5. The manometer of claim 1 in which the pipes of the first pair incline toward each other to form a V-shaped conduit and the pipes of the second pair are inclined toward each other with their upper ends approaching each other, said pipes together outlining a quadrangle, and said valve means is a rotary valve comprising a valve seat and a valve member cooperating therewith, the upper ends of the pipes of the second pair opening into the valve seat,

and means in said valve member for closing off the said upper ends when the valve member is in one position and opening said upper ends simultaneously when said valve member is moved to another position.

6. The manometer of claim 1 in which said pipes comprise bores in a block of material impervious to said fiuid.

'7. The manometer of claim ti in which said material is transparent.

8. The manometer of claim 6 in which said material is a transparent synthetic resin.

9. The manometer of claim 4 in which said pipes comprises bores in a block of material impervious to said fluid, and said valve seat is formed in the block.

10. The manometer of claim 9 in which said material is a transparent synthetic resin.

11. A manometer comprising a body of transparent synthetic resin having first, second, third and fourth bores therein, and a valve seat formed in the top portion of the body; said first and second bores angling toward each other and meeting at their lower ends to form a V-shaped conduit, with their upper ends opening in the top of the body; said third bore having its lower end connecting with the first bore between the upper and lower ends of the latter, and having its upper end opening into the valve seat; said fourth bore having its lower end connecting with the second bore between the upper and lower ends of the latter, and having its upper end opening into the valve seat; a valve member cooperable with the valve seat and being provided with fluid passages therein, said fluid passages being so positioned that. when the valve memher is in one position with respect to the valve seat, the openings of the upper ends of the third and fourth bores in the valve seat are closed, but when the valve member is moved to another position, said fluid passages connect with said openings simultaneously.

.12. The manometer of claim 11 in which said fluid passageways are grooves formed in the peripheral surface of the valve member, the grooves being long enough to intersect said openings at their lower ends and to extend above the surface of the body at their upper ends.

13. The manometer of claim 11 in which said fluid passageways constitute a bore extending through the valve member with the ends of the bore opening on the peripheral surface thereof.

References Cited UNITED STATES PATENTS 913,321 2/1909 Thomas 73-401 2,594,649 4/1952 Hodshire '7340l 3,313,157 4/1967 Gilson 73-401 LOUIS R. PRINCE, Primary Examiner. DONALD O. WOODIEL, Assistant! Examiner, 

1. A MANOMETER COMPRISING FIRST AND SECOND PAIRS OF PIPES EACH PIPE OF THE FIRST PAIR HAVING AN UPPER AND LOWER END, THE LOWER ENDS OF THE FIRST PAIR OF PIPES BEING CONNECTED TO EACH OTHER, AND END OF EACH OF THE SECOND PAIR OF PIPES CONNECTING INTO THE WALLS OF THE PIPES OF THE FIRST PAIR AT POINTS BETWEEN THE UPPER AND LOWER ENDS OF THE LATTER; A FLUID IN THE LOWER PORTIONS OF THE PIPES OF THE FIRST PAIR; AND VALVE MEANS ASSOCIATED WITH THE OTHER ENDS OF THE PIPES OF THE SECOND PAIR FOR CLOSING THE LATTER ENDS, SAID MEANS BEING MOVABLE TO OPEN THE LATTER ENDS SUBSTANTIALLY SIMULTANEOUSLY TO THE SAME GAS PRESSURE EXTERNAL OF THE MANOMETER. 